How Can Water Scarce Cities Thrive in a Resource Finite World? Strategies and Solutions

Water scarcity is not a new concept, nor a new phenomenon. History provides us with many examples of cities and countries facing challenges to securing stable and reliable fresh water supplies.

However, current trends challenge water managers and decision makers in new ways – from progressive depletion and deterioration of water resources to drastic changes in hydrology due to climate change. In fact, water practitioners recently gathered in Brasilia, Brazil for the World Water Forum and World Water Day 2018 to discuss the world’s most pressing water issues. Recent crises in Cape Town, South Africa and Rome, Italy provided a backdrop and served as a reminder of the urgency with which water resilience is needed.

Despite such concerning events, water demands are skyrocketing as cities expand, draining already scarce resources — and water scarce cities are edging closer and closer to running dry. And, although a number of water scarce cities are actually beating the odds, their stories often remain undocumented, unavailable, and inaccessible.

A new World Bank report illuminates such valuable experiences to fill this important knowledge gap about the failures, successes, and innovative solutions of water scarce cities across the world. The report provides a cross-case analysis that dives into knowledge from over 20 case studies (to be published soon), to compare and contrast water resource challenges, technical solutions, and institutional mechanisms. In so doing, the report creates new knowledge and identifies the key drivers of positive change — including how governance, capacity, or technological changes were addressed.

Through a review of some of the cities and states already beating water scarcity odds, the report encourages water scarce cities to adopt urban water scarcity management approaches that include:

Demand management and infrastructure efficiency

Innovative surface and groundwater management

Non-conventional water resources

Cooperation with other users

Adaptive water system designs and operations

Water scarce cities solutions do not have to be high-tech, expensive, or complex. However, solutions must work – and even better if solutions work together. This report turns traditional urban water security approaches on their head, and shows that there is not a one-size-fits-all pathway to urban water security.

Innovation across water scarce cities is required to beat bleak water futures. Through an analysis of urban water security in scarcity contexts, the report shines a light on existing solutions and interprets information in new and powerful ways.

By illuminating sophisticated water-secure visions and strategies, the report aims to inspire further pioneering actions across all water scarce cities – to bend the curve towards a water-secure world for all.

But the study also warns that while trees can mitigate the effect of air
pollution, deposits of air pollutants on leaves can also affect photosynthesis
“and therefore potentially affect pollution removal by trees”. As with
everything, balance is key.

The cooling effect of trees

Trees can also significantly cool temperatures in cities. In hot
climates, tree cover can reduce energy expenditure on air conditioning, while
driving down the consumption of air polluting fossil fuels that power these
cooling systems. Experimental investigations and modelling studies in the United States have shown that shade from trees can reduce
the air conditioning costs of detached houses by 20–30 per cent.

“Trees could reduce temperatures in cities up to 8°C, lowering use of
air conditioning and related emissions by up to 40 per cent,” says Simone
Borelli, an Agroforestry and Urban/Periurban Forestry Officer with the Food and
Agriculture Organization of the United Nations.

“When part of a wider landscape mosaic, large green patches within and
around cities would also reduce emissions through avoided sprawl and excess
mobility requirements,” he adds.

Urban tree-planting has to be done right. Species planted should be ones
that are most effective at trapping pollution, typically those with large
leaves. Officials also need to account for things like wind patterns and tree
spacing. If water is scarce, they’ll want to consider drought-tolerant
varieties, and avoid trees that increase pollen and allergies.

Action is all the more important given that urbanization is
accelerating—the proportion of people living in cities will be 60 per cent in
2030 and 66 per cent in 2050. Nearly 90 per cent of this increase will occur in
Africa and Asia. To address the impacts of this rapid growth and the related
challenges, a large-scale effort is needed.

Building the
Great Green Wall of Cities

Nearly 8,000 km long and 15 km wide, the Great Green Wall is an African-led movement of epic proportions initiated in 2007 to
green the entire width of northern Africa, a semi-arid region extending
from Senegal to Djibouti. A decade in and roughly 15 per cent under way, the
initiative is slowly bringing life back to some of Africa’s degraded
landscapes, providing food security, jobs and a reason to stay for the millions
who live along its path.

An initiative of this nature in urban areas is being developed by the
Food and Agriculture Organization and other partners in preparation for the UN
Climate Summit in September 2019. It aims to create up to 500,000 hectares of
new urban forests and restore or maintain up to 300,000 ha of existing natural
forests in and around 90 cities of the Sahel and Central Asia by 2030. Once
established, this “Great Green Wall of Cities” would capture 0.5–5 gigatonnes
of carbon dioxide per year and stock carbon for centuries.

“UN Environment promotes the planting of trees as a key way to mitigate
climate change and boost land-based biodiversity, 80 per cent of which is in
forests,” says Tim Christophersen, head of UN Environment’s Freshwater, Land
and Climate Branch, and Chair of the Global Partnership on Forest and Landscape
Restoration. “We are working with partners across the
planet to boost tree planting for ecosystem restoration. There is scope for
planting one trillion more trees, in addition to the 3 trillion that already
exist on Earth. But it has to be done right; planting indigenous trees,
supported by local communities, is a good way to go.”

Let the stones gather some moss

In those forest ecosystems, trees are not alone in cleaning the air. An
ambitious project by Greencity Solutions in Berlin, Germany, seeks to marry
high-tech applications with another natural air purifier: moss.

“The ability of certain moss cultures to filter pollutants such as
particulate matter and nitrogen oxides from the air makes them ideal natural
air purifiers,” says Greencity Solutions.

“But in cities, where air purification is a great challenge, mosses are
barely able to survive due to their need for water and shade. This problem can
be solved by connecting different mosses with fully automated water and
nutrient provision based on unique Internet of things technology,” it explains.

Or by planting more trees that will provide the cover and humidity, that
will help moss take hold and grow.

Related

New study expected to chart Melaka’s pathway to urban sustainability

Within the framework of the ‘Sustainable City Development in Malaysia’
project, which seeks to address the country’s urban challenges and which is
being implemented by the United Nations Industrial Development Organization
(UNIDO), executed by the Malaysian Industry-Government Group for High
Technology (MIGHT), and supported by the Global Environment Facility (GEF), the ‘Melaka Sustainability Outlook Diagnostic: Pathway to Urban
Sustainability’ was launched today. The report is the result of an assessment
performed by the World Bank’s Global Platform for Sustainable
Cities (GPSC) in which Melaka actively participates.
The study will inform the Melaka State’s Structure Plan and its long-term
planning document; it will also offer key recommendations for the State to
chart its own pathway to urban sustainability.

The diagnostic consists of an overview report containing a policy brief,
an executive summary and a benchmark assessment as well as six supporting
reports that cover each of the diagnostic’s dimensions, namely Reinforcing
Melaka’s Economic Success; Integrating Environmental Plans; Enhancing Housing
and Services; Shaping a Compact, Efficient, and Harmonious Urban Form; Shifting
Melaka’s Mobility Modal Split; and Demonstrating Fiscal Sustainability.

One of the report’s recommendations calls for the State and the City of
Melaka to obtain a credit rating; accordingly, both entities already agreed to
undergo a formal rating assessment with UNIDO’s support. Depending on the
assessment’ result, they could tap capital markets to finance future
infrastructure projects. Moreover, another recommendation calls for the City of
Melaka to complete a climate-smart capital investment plan for which the city
indicated its willingness, with UNIDO coordinating local and national inputs to
raise funds.

Being one of most urbanized countries in Asia, 75 percent of Malaysians
reside in urban areas and over 90 percent of the national economic activities
are conducted in cities. Rapid urbanization has created tremendous economic
opportunities for the country, but has also put enormous pressure on its urban
infrastructure and services.

Related

Make Dhaka Walkable

When it comes to urban mobility, Global
South cities suffer significant challenges such as lack of transport equity and
poor accessibility for the urban poor. On the March of 25-28, 2019, the Share
the Road Programme (a partnership between UN Environment and FIA Foundation)
participated in a workshop dubbed ‘make Dhaka walkable’ held in Dhaka,
Bangladesh, organized by the Sustainable Transport Equity Partnerships (STEPS)
– a global alliance of researchers and practitioners including the Walk21
Foundation, UN Environment and the University of Leeds. The organizations are
committed to identifying the essential steps decision makers and
multi-disciplinary teams of experts must collectively take to meet the needs of
people walking. STEPS aims to promote urban transport systems that can meet the
travel needs of low income, city populations in the Global South.

Despite walking making up to 75% of all journeys, the conditions in
which people walk in Dhaka are often unsafe and unpleasant. In order to
highlight the needs of pedestrians in Dhaka, the meeting brought together
engineers, planners, civil rights activists, NGOs, social scientists and many
more for a real interdisciplinary perspective of the transferability of global walkability
practices.

The opening workshop included representatives from Dhaka Transport
Coordination Authority (DTCA), Road Transport and Highways Division, Ministry
of Road Transport and Bridges, University of Asia Pacific and others to help
push the local walking agenda forward.

A study visit was also conducted in the Korail slum in Dhaka, to
assess the real insights into the walking and accessibility issues affecting
local, low income communities.

One of the gaps identified through the STEPS programme is the severe
inadequacies of non-motorized transport in transport policy in the Global
South. The Share the Road programme shared knowledge on the experience of
non-motorized transport in Nairobi -the small initiatives needed to make big
differences, the need to have NMT users included in the planning of road
construction projects, and the importance of securing a percentage in transport
budgets. The vital and economic aspects of walkability projects cannot be
ignored.

Having discussed the ‘eight steps to walkable Dhaka’ facilitated by
Walk21, the workshop was brought to a close by Professor Jamilur Choudhury from
University of Asia Pacific who gave some personal
reflections on the development of transport policy and walking in the city, and
stated his commitment to moving the walkability agenda forward locally.